It is not surprising that Michael Boxall isn't counting his chickens just yet.

The 25-year-old defender has been a professional footballer for four years, yet he has made just 26 first-team appearances in that time: 19 for the Vancouver Whitecaps and seven in two seasons for the Wellington Phoenix.

That leaves a lot of days watching matches in a suit, so Boxall had to be convinced when he was informed that coach Ernie Merrick had confirmed him as his right-back for tonight's home game against the Central Coast Mariners.

"Did he really? Oh, that's cool," said Boxall, a centre-back who gets the first shot at replacing Louis Fenton, out for the season with a shoulder injury.

"Obviously I'm very excited if I do get to play there, it's been a few drinks in between games for me. There's no secret there. But I came on and felt OK against Western Sydney [after Fenton got injured on New Year's Day]. I'm sure I'll get a bit more comfortable in the role and I'll just be buzzing to get back amongst it."

Boxall said he hadn't started a game at right-back for "eight or nine years".

But he took confidence from the fact that Merrick had shown patience and belief in Fenton, who made the conversion from an attack-minded winger.

"So I'm sure with a few pointers here and there, I should be all right."

Tackling and man marking comes naturally for Boxall, who also has seven caps for the All Whites. But the more difficult part of the transition would be forcing himself to push forward and attack.

"The first few minutes of the second half against the Wanderers, my natural inclination was to go backwards a bit too often. Ernie told me to trust my abilities and get forward and get involved, and take on the wingers. I did that a few times and didn't feel too out of place."

At 1.88 metres and "pushing 90 kilograms", Boxall is one of the biggest players in the A-League, let alone fullbacks.

But he combines that size with an explosive athleticism; he ranks alongside Tyler Boyd as the quickest Phoenix player.

"The numbers don't lie, mate," he quipped.

"We've had a bit of speed testing and I guess that's what it showed. It's just smashing it in the weights room, I think, squats. It's not like I do speed work on the field, it's mostly the gym stuff that seems to help out."

Boxall's only other start this season was in round one, a 2-1 loss to the Brisbane Roar when captain Andrew Durante was away on All Whites duty.